๐งฎFree Calculators & Math Tools Online
Free online calculators for everyday math: percentage calculators, unit converters, number base converters, and financial calculations. Type in your numbers and get instant results in your browser โ no signup needed.
25 free calculators & math tools below โ pick one to get started.
Number Base Converter
Computer science students, embedded systems programmers, and network engineers frequently convert numeric values between decimal notation and positional numbering systems like binary, octal, and hexadecimal. Performing radix conversions by hand using repeated division or powers of two is tedious and prone to calculation mistakes, especially when troubleshooting memory offsets, bitmasks, or hardware register configurations. Number Base Converter streamlines this process by accepting an input integer in binary, octal, decimal, or hexadecimal and converting it simultaneously across all four standard computing bases. Number Base Converter runs locally in your browser using client-side JavaScript. The tool does not intentionally send entered numerals or converted values to our servers.
Currency Exchange Rate
Currency Exchange Rate is a live FX calculator that converts an amount between 12 common currencies: USD, CNY, EUR, JPY, GBP, KRW, HKD, SGD, THB, VND, IDR, and MYR. Enter an amount, pick the From and To currencies, and click Convert to see the converted total alongside the current rate and the date the rate was published. Rates come from the free ExchangeRate-API endpoint (open.er-api.com, no API key required), fetched directly by your browser. Because the rates are live data from a third-party service, this tool needs an internet connection to work.
Salary Converter
A $25 hourly wage sounds modest until you multiply it out โ but few people do the arithmetic on the spot. Salary Converter turns an hourly wage into annual, monthly, daily, and hourly-equivalent figures the moment you type, using your own hours-per-week and weeks-per-year assumptions plus an optional tax rate for after-tax estimates. With the defaults (40 hours a week, 52 weeks a year, 20% tax), typing 25 shows $52,000 a year and $41,600 after tax. There is no button to press; every card updates live as you edit. It runs locally in your browser, so your pay details stay on your device.
Loan Calculator
Evaluating mortgage proposals, auto loans, or personal financing options requires understanding how monthly obligations, interest rates, and loan terms interact over time. Many online loan calculators require submitting personal contact details, display aggressive financing advertisements, or transmit financial queries to remote lead-generation servers. This Loan Calculator evaluates standard fixed-rate amortized loans directly within your browser. It calculates exact monthly payments, total interest costs, and cumulative repayment amounts while generating a 12-month amortization schedule locally, helping you compare financing options privately and transparently.
Compound Interest Calculator
Forecasting long-term investment growth, retirement portfolios, and savings accounts requires modeling the compounding effect of interest earned on accumulated interest over time. Many commercial investment calculators clutter the screen with brokerage promotions or require submitting financial assets to lead-capture forms. This Compound Interest Calculator computes future portfolio values directly in your browser. It models regular periodic contributions across annual, quarterly, monthly, and daily compounding frequencies, generating an annual growth projection table locally to help you evaluate investment horizons with complete privacy.
BMI Calculator
Body mass index (BMI) is a commonly used screening measure that compares an adult's body weight with height. Calculating it manually requires converting units, squaring the height measurement, and applying the correct formula. This browser-based adult BMI calculator updates the result as you enter your measurements. Choose metric units (kilograms and centimeters) or imperial units (pounds and inches), then review your BMI and corresponding adult screening category. BMI is not a diagnosis and should be interpreted together with other health information.
UUID / GUID Generator
Engineering distributed systems, relational databases, and modern APIs demands unique identifiers that do not collide across independent microservices. Relying on auto-incrementing database integers creates scaling bottlenecks, exposes record counts to external observers, and complicates offline record creation. Universally Unique Identifiers (UUIDs) resolve this challenge by generating 128-bit values with astronomical mathematical distinctness. This browser-based UUID generator produces fresh, standard identifiers on demand. Whether you need an idempotency key for payment requests, mock records for unit tests, or primary keys for database migrations, you can generate and copy IDs effortlessly.
Sum Calculator Online โ Free Number Addition Tool
Quickly totaling a list of numbers from an invoice, calculating the average of experimental measurements, or determining the minimum and maximum figures in a batch of numbers often involves opening spreadsheet software or tapping through a handheld calculator repeatedly. When numbers are scattered across text notes, emails, or comma-separated lists, manual data entry is slow and vulnerable to typographical errors. Number Sum Calculator eliminates this friction by parsing numbers from arbitrary text input in real time. It extracts values separated by spaces, commas, or line breaks and dynamically displays sum, count, average, minimum, and maximum values. Number Sum Calculator runs locally in your browser using client-side JavaScript. The tool does not intentionally send numeric entries or statistical calculations to our servers.
Random Number Generator Online โ Free Secure Random Numbers
Generating random numbers is a frequent requirement in scientific sampling, raffle drawings, board games, cryptographic key testing, and software simulation. Relying on basic pseudo-random number generators can introduce statistical skew or predictable outcomes that undermine fairness. Random Number Generator runs locally in your browser using client-side JavaScript. The tool does not intentionally send generation parameters or produced numbers to our servers. Powered by the Web Cryptography API, it draws entropy directly from your operating system to generate numbers within any specified minimum and maximum range, featuring unique-number constraints and convenient copying as comma-separated values or line-separated lists.
Byte Converter Online โ Free Data Size Calculator
File sizes, disk quotas, and memory specs are quoted in a mix of B, KB, MB, GB, TB, and PB, and converting between them by powers of 1,024 is nobody's idea of fun. Byte Converter takes one value in any of those six units and shows its equivalent in all six at once โ enter 1.5 GB and you immediately see the KB, MB, TB figures beside it. The math uses the binary convention (1 KB = 1,024 bytes) that operating systems and developers use, with results shown to up to four decimals. One input, one Convert click, six answers, all computed locally in your browser.
Number to Words Converter
Writing legal contracts, drafting financial checks, issuing commercial invoices, and preparing official receipts often mandates spelling out numeric amounts in formal English words. Transcribing numbers like account balances or payment figures into words by hand is slow and fraught with spelling mistakes or forgotten place values. A single misplaced hyphen or omitted scale name on a formal financial document can cause compliance disputes or check processing rejections. Number to Words automates this task by converting any whole integer up to 999,999,999,999 into clear, grammatically correct English words. Number to Words runs locally in your browser using client-side JavaScript. The tool does not intentionally send integer inputs or spelled-out text to our servers.
Arithmetic Sequence Generator
An arithmetic sequence โ each term increasing by a fixed difference โ shows up in pagination logic, test data, scheduling intervals, and math homework. The Arithmetic Sequence Generator builds one for you from three inputs: the first term, the common difference, and how many terms you want. Defaults of 1, 2, and 10 give you 1, 3, 5, 7 โฆ out of the box, and you can use negative or zero differences for decreasing or constant sequences. The result is a comma-separated list ready to paste into code, spreadsheets, or documents. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your numbers to our servers.
Random Port Generator
When spinning up local dev servers, Docker containers, or test services, you often need a port number that is valid but unlikely to collide with common defaults. The Random Port Generator produces random port numbers in the full valid range of 1โ65535, one per line. Set the Count field (up to 100) to get a batch at once โ useful when configuring multiple services or generating candidate ports to try. Each click produces a fresh set of random values. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send anything to our servers.
Percentage Calculator
Calculating percentage portions, relative proportions, and percentage changes is a frequent daily requirement across business reporting, retail shopping, invoice verification, and academic coursework. Performing multi-step percentage formulas manually often leads to mental math mistakes, while searching for online calculators frequently lands on ad-cluttered websites with intrusive popups. This Percentage Calculator evaluates standard percentage problems directly within your browser. It supports calculating percentages of values, proportion shares, and rate of change between two numbers, providing clear and immediate results locally.
Age Calculator
Figuring out someone's age in whole years is straightforward subtraction, but determining an exact chronological age in years, months, and days is tricky. Varying month lengths, leap year cycles, and calendar shifts turn precise age verification into an annoying mental puzzle. Whether you are filling out official passport documents, determining school enrollment eligibility, verifying insurance brackets, or calculating an infant's developmental milestones, precision matters. This age calculator removes guesswork by processing your birthdate against the calendar. Enter your date of birth, click the calculate button, and review your exact age breakdown in completed years, months, and days.
Roman Numeral Converter
Roman numerals still appear in copyright dates, chapter headings, clock faces, and formal outlines โ and converting them by hand invites errors. The Roman Numeral Converter works both directions: type a number (1โ3999) and get its Roman form, or type a Roman numeral like MMXXIV and get the Arabic value. Conversion follows standard subtractive notation (IV for 4, IX for 9, XL for 40, CM for 900). Out-of-range numbers get a clear "Enter 1โ3999" message, since traditional Roman numerals do not extend beyond that. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your input to our servers.
Length Converter
Switching between metric and imperial lengths โ centimeters to inches, miles to kilometers โ comes up in DIY projects, travel planning, product specs, and homework. The Length Converter translates among eight units: millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. There is no button to press: type a value, pick the From and To units, and the result updates live as `1 m = 3.28084 ft`. Results show up to six decimal places with trailing zeros trimmed, and invalid input displays a simple "โ". Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your input to our servers.
Weight Converter
Converting mass and weight figures across metric and imperial systems is an everyday task for cooking, shipping, scientific work, and manufacturing. The Weight Converter offers a direct way to switch between six standard weight units: milligrams, grams, kilograms, ounces, pounds, and metric tons. Because the tool updates live as you type, there is no need to submit a form or press a conversion button. Simply type your quantity into the Value field, choose your starting and target units from the dropdown menus, and read the converted figure. If you enter non-numeric text, the display gracefully falls back to a dash. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your weight values or conversion inputs to our servers.
Temperature Converter
Temperature scales differ across regions and scientific disciplines, making reliable conversion essential for cooking, weather forecasting, chemistry, and international travel. The Temperature Converter translates temperature readings between Celsius (ยฐC), Fahrenheit (ยฐF), and Kelvin (K). The tool updates live as you enter values, removing the friction of clicking buttons or refreshing web pages. By converting input values through a standardized Celsius pivot formula, it delivers accurate results between any pair of supported scales. The calculated value is presented formatted to two decimal places, such as 0ยฐC = 32.00ยฐF. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your temperature values to our servers.
Speed Converter
Velocity measurements vary widely between road transport, aviation, maritime navigation, and scientific research. The Speed Converter provides quick translation across five distinct velocity units: meters per second (m/s), kilometers per hour (km/h), miles per hour (mph), knots (knot), and feet per second (ft/s). Conversion occurs live as you adjust numbers or switch dropdown units, requiring no button clicks. By using meters per second as an internal base unit, the tool delivers balanced transformations between metric, imperial, and nautical figures. Results appear formatted to four decimal places, such as 100 km/h = 62.1371 mph. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your speed values or velocity inputs to our servers.
Volume Converter
Translating liquid capacities between metric measurements and United States customary units can be tricky when preparing recipes, dosing liquids, or reading product specifications. The Volume Converter bridges this gap by supporting seven standard volume units: milliliters (ml), liters (L), US cups (US cup), US gallons (US gal), US fluid ounces (US fl oz), tablespoons (tbsp), and teaspoons (tsp). Conversions happen live as you type or switch options, eliminating the need to click a submit button. Using milliliters as a common baseline, the converter transforms quantities cleanly and displays results formatted to four decimal places, such as 1 L = 4.2268 US cup. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your volume measurements to our servers.
GST / VAT Calculator
Calculating goods and services taxes or value-added taxes is a regular requirement when invoicing clients, reviewing merchant receipts, or preparing accounting records. The GST/VAT Calculator handles both forward and reverse tax computations using clean mathematical formulas. By entering an Amount and a tax percentage in the % field (defaulting to 10), you can select between two modes: Add tax or Extract tax. In Add tax mode, the tool calculates total with tax as amount ร (1 + rate) and tax as amount ร rate. In Extract tax mode, it computes pre-tax value as amount รท (1 + rate) and tax as amount โ amount รท (1 + rate). All values appear with two decimals. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your financial figures or tax values to our servers.
Calorie Calculator (BMR / TDEE)
Planning a nutrition plan or fitness routine requires understanding how many calories your body burns at rest and through daily activity. The Calorie Calculator estimates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the scientifically validated Mifflin-St Jeor equation. By entering your Weight kg, Height cm, and Age, choosing Male or Female, and selecting from four activity levelsโSedentary (1.2), Light (1.375), Moderate (1.55), or Active (1.725)โclicking Calculate computes your daily energy needs. Results appear rounded to whole numbers as BMR: X kcal/day and TDEE: Y kcal/day. Everything runs locally in your browser using client-side JavaScript. The tool does not intentionally send your personal physical stats or biometrics to our servers.
Tip Calculator
Splitting a restaurant bill can become confusing when you need to calculate a tip and divide the final amount among several people. A small arithmetic or rounding mistake can leave the group total short or produce a different gratuity than intended. This tip calculator calculates the tip amount, final bill, and estimated per-person share in one step. Enter the bill amount, choose a tip percentage, specify how many people are splitting the total, and review the results right away.
Binary Calculator
Software developers, network engineers, and computer science students frequently need to compute arithmetic and bitwise logic operations on raw binary values. Calculating binary addition with carries, subtraction, or bitwise masking (AND, OR, XOR) by hand is time-consuming and error-prone. Converting binary numbers into decimal values manually adds friction during network subnetting or low-level debugging. This Binary Calculator evaluates arithmetic and bitwise operations between two binary inputs directly in your browser. It displays both binary and decimal results simultaneously, providing quick verification on your local machine.